1. Field of the Invention
The present invention relates to new substituted-amido derivatives, method for preparation of the derivatives and fungicides for agricultural and horticultural use containing the same as an active ingredient.
2. Description of the Prior Art
One important problem in agricultural production, especially in culture of fruit trees and vegetables, includes diseases caused by phytopathogenic fungi of Phycomycetes (for example, Pseudoperonospora-caused diseases, Phytophthora-caused diseases, etc.). The diseases caused by these fungi are known to be difficult to protect against because of the special physiological and biological properties of the fungi, and therefore, the development of accepted chemical agents capable of protecting against the fungi is desirable. The extent of damage caused by the fungi of Pseudoperonospora or Phytophthora is great as broadly covering various crops, and the damage is extremely serious.
At present, captan (common name), captafol (common name), dithiocarbamate fungicides (for example, zineb (common name), etc.), chlorothalonil (common name), etc. are being widely used against diseases caused by phytopathogenic fungi of Phycomycetes. However, these fungicides are essentially for the purpose of prevention of diseases and could not almost be expected to have a curative effect, and therefore, these have a fatal defect in that these could not display a sufficient effect when they are applied to diseased plants. A fungicide of an acylalanine series compound, which has recently been developed, for example, metalaxyl (common name), etc., has both a preventive effect and a curative effect. However, tolerant fungi against the fungicide were already present, and therefore, the protective effect of the fungicide has become fairly lowered.
Hitherto, substituted-amido acetonitrile derivatives, substituted-amido thioacetamide derivatives and substituted-amido N-acylthioacetamide derivatives, which are considered to be similar to the compounds of the present invention in view of chemical structures, have already been reported in Japanese Patent Application Laid-Open Nos. 167978/82 (U.S. Pat. No. 4,432,784), 69866/83 (U.S. Pat. No. 4,515,959) and 255759/85 (the term "OPI" as herein referred to means a "published unexamined Japanese patent application"). However, the prior art cannot be said sufficient to provide any practical fungicides for agricultural and horticultural use, and in particular, the known compounds would impart some chemical phytotoxicity against crops, which is one serious outstanding problem.